The present invention relates to a driving control method for driving a medium, such as a head driving apparatus for a thermal printer or an ink jet printer, a CCD driver, a motor driver or a liquid crystal driver, which is operated in accordance with data or a driving signal, and a driving control apparatus.
As a driving control apparatus of the foregoing type, a head driving apparatus for an ink jet printer is known. In general, a head driving apparatus (not shown) of the foregoing type incorporates a shift register, which constitutes a buffer for two lines, and a latch circuit. Moreover, the head driving apparatus incorporates an ink jet head formed by disposing ink chambers of the ink jet head, an AND gate for outputting an energizing signal in accordance with an output of the latch circuit and an energizing enable and an amplifier which amplifies an output from the AND gate to output a driving waveform from each output pin.
In order to realize an original operation, serial data, a data transmission enable and a system clock, which are supplied to the shift register, must be input to the head driving apparatus of the foregoing type. A latch signal must be input to the latch circuit. An energizing enable must be input to the AND circuit in order to provide operation timing. Thus, a driving waveform for driving an ink chamber of the ink jet head is supplied from the AND circuit through the amplifier. Note that a data transmission clock may be employed as a substitute for the data transmission enable.
As a head driving apparatus for performing multi-drop gray-level driving, for example, 8-bit gray-level energizing signal for expressing the gray-level is supplied to a selector circuit for specifying the gray-level level.
In either case, the conventional head driving apparatus has a problem in that a multiplicity of control signals to drive the ink chambers of the ink jet head are required as well as serial data, the clock signal and the reset signal.
As described above, the number of signal lines for driving the head is increased as the head driving apparatuses which must be connected is increased. Therefore, an excessively large number of cables and connector pins is required. That is, the cables and connector pins are increased as the signal lines required to drive the head is increased. Hence it follows that noises are increased. Thus, there arises a problem in that the dependability, such as contact reliability, deteriorates and the cost is enlarged.